This invention relates to laser aiming devices for firearms, and particularly to compact laser aiming assemblies providing adjustments for elevation and windage.
Laser sighting devices for firearms have been in use for some time. Basically, a laser, which emits a relatively powerful, narrow beam of light that expands minimally over a long distance, is mounted on a firearm, such as a hand gun or rifle, so as to illuminate the target with a spot of light where the bullet will strike the target. While the laser beam will, for all practical purposes, follow a straight line, the bullet will follow a ballistic trajectory so that, despite high muzzle velocity, at long distances the trajectory of the bullet will deviate significantly from a straight line. Also, the laser must necessarily be mounted to the side of the barrel of the firearm, which means that the laser beam cannot propagate in the same plane as the trajectory of the bullet. Consequently, it is necessary to aim the laser beam so that, for a given distance, the beam will illuminate the target with a spot at the position where the bullet will be after traveling that distance. The vertical angular setting of the laser beam is known as “elevation” and the lateral angular adjustment of the beam is known as “windage.”
Various laser sighting devices are known that provide not only for setting the elevation and windage of the sighting laser beam, but also for convenient adjustment of those settings in the field. For example, Chen, U.S. Pat. No. 5,784,823, discloses a laser centrally mounted in a semi-spherical fixture which is disposed in a casing. The laser is positioned in the casing by rotation of the fixture therein, and held at the desired angle by frictional force. Thummel, U.S. Pat. No. 5,581,898, discloses a laser module disposed within a housing adapted to be mounted on a firearm, wherein the back of the laser module is seated in the back of the housing and orthogonal set screws are positioned to move the front of the module up and down, and back and forth, to set the elevation and windage, respectively. Jehn, U.S. Pat. No. 5,323,555, discloses a similar mechanism. Baikrich, U.S. Pat. No. 5,253,443, also discloses a laser sighting device having a laser module disposed in a housing and seated against the back of the housing, but the front of the module is moved laterally by longitudinally moving cam members having threads which engage axially rotatable rings disposed around the housing.
Devices such as these suffer from at least two limitations. One limitation is that the laser is typically disposed so far into the housing that its exit window is difficult to clean. Another limitation is that since the front of the laser module must move laterally, a large exit window is required for the housing, which places a limit on how small the housing can be. In general, these devices are fairly large, and are therefore limited in how and where they can be mounted on a firearm.
Accordingly, it has been found desirable to provide a laser sighting device that is easier to clean, and to provide a more compact laser aiming assembly so that a sighting device can be mounted at the most convenient location on a firearm.